Tuesday, 22 November 2011

2.60a Phagocytosis

Describe how the immune system responds to disease using white blood cells, illustrated by phagocytes ingesting pathogens and lymphocytes releasing antibodies specific to the pathogen.

The process starts with a white blood cell and you can recognise white blood cells through the lobuded nuclues.

Phacytosis is the first line of defense of our body, it defends us against bacterias in our blood stream. The white cell can detect the presence of the bacteria because of the chemical the bacteria gives off.

The consequence is that the Phagocyte (white blood cell), the chemical stimulus starts the cell to surround the bacteria cells. The extention is called the Pseudopodia. If we move on to the next stage, the bacteria is closed by the cell membrane of the Phagocyte - this is called the fuse stage.

This leads to the next stage which is bacteria enclosed which is called the vescicle. The next step is that the white cell will introduce enzymes which will destroy the bacterial cell. What often happens is that the white cell is excrete and release the fragment of the dead bacteria.